Abstract: Parameters of EEG activities that could be related to a better attention concentration were compared in two groups of young men, one of which included adequately coached amateur boxers and another consisted of students that were not involved in boxing. The EEG signals were registered from the Cz point in accordance with the 10-20 system; the theta/beta and theta/sensorimotor rhythm (SMR) ratios proved to be especially important for purposes of analysis. Research media included a FlexComp Infinity coder and an EEG-Z sensor with an automatic impedance function. The results were evaluated by means of BioGraph Infinity. The obtained results allow us to conclude that adequately coached amateur boxers who are successful achieve lower theta/beta ratio and theta/SMR ratios than control group students not involved in boxing. One can suggest this is due to the better attention concentration in the boxers (despite posible head injuries) compared to the control group.PubDate: 2015-01-15

Abstract: We assessed the effect of sleep deprivation on the pain thresholds in the thermal and chemical nociceptive tests. Adult male Wistar rats and mice were randomly assigned to the three groups, with no sleep deprivation (control), subjected to 24-h-long sleep deprivation, and sleep-deprived and treated with either an H2 (histamine) receptor antagonist, cimetidine, or a cholinergic receptor blocker, atropine, before deprivation. Sleep deprivation led to significant decreases in both hot plate and tail withdrawal latencies in the thermal tests, a significant increase in the number of writhings in the acetic acid-induced writhing test, and significant prolongation of the licking time in the formalin test (P < 0.05 in all cases). All changes in the thermal and chemical tests denote noticeable hyperalgesia. Prior administration of both cimetidine and atropine significantly reversed these hyperalgesic changes caused by sleep deprivation as revealed by increases in the thermal latencies in both tests used. We, therefore, conclude that both histaminergic and cholinergic systems play significant roles in sleep deprivation-induced hyperalgesia.PubDate: 2015-01-15

Abstract: This paper reviews studies on the face inversion effect and expertise. It is suggested that the inversion effect be considered as evidence of specific processing in face recognition or expertise of the objects, which meet three prerequisites. Some disputes are also pointed out in the review. It is proposed that further studies should be addressed to the visual differences, physiological basis of cognitive modules, and anatomical and functional location of the respective networks.PubDate: 2015-01-15

Abstract: We used a network theory approach, based on the dynamic core hypothesis (DCH), to study the thalamo-cortical loop (TCL) and its subsets regarding their role in consciousness. We used the Collation of Connectivity Data on the Macaque Brain (CoCoMac) and calculated the degree distributions, transmission coefficients, connection density, clustering coefficients, path lengths, and modularity. Our results showed that the TCL and cortex exhibit exponential degree distributions, and the ratio of efferent/afferent connections in the thalamus is smaller than 1.0 This may support the notion that the connections received by the thalamus from the cortex play a key role in improving information processing in the conscious states. The average values of transmission coefficients for the cortex and TCL were found to be equal to 1.49 and 1.28, respectively. This indicates that: (i) the cortex is a system that mainly transmits information outward rather than receives it; (ii) the TCL is a cooperative system that performs this in a give-and-take manner; (iii) connections of the cortex are denser than those in the TCL, showing that the cortex might be advantageous for processing of complicated information during consciousness; (iv) both the TCL and cortex are small-world systems; (v) the scaled value of the characteristic path length in the TCL is smaller than that in the cortex, which implies a higher speed potential for information processing in the TCL than in the cortex; (vi) the scaled value of the clustering coefficient is nearly the same in the cortex and TCL, and (vii) the number of modules is 5 in the cortex and 6 in the TCL.PubDate: 2015-01-15

Abstract: Alzheimer’s disease is a neurogenerative disease characterized by significant worsening of memory, disorders in the emotional sphere, and impairment of cognitive and motor functions. Agonists of NMDA receptors are used as potential therapeutic agents for correction of the above disorders, and memantine is one of such drugs. This agent decelerates the progressive development of neurodegenerative processes. It demonstrated a neuromodulatory action on motor behavioral phenomena in 2- and 13-month-old rats placed in nowel conditions of free behavior; estimation was performed before and after peroral introduction of 10 mg/kg memantine. Videorecording of the animals’ behavior with subsequent analysis of the records was used in the experiments. According to the obtained data, memantine decreased, in general, motor activity of the rats, increased the duration of episodes of their quiet standstill state, and, simultaneously, somewhat increased the intensity of research phenomena. These results show that memantine weakens the state of fear and anxiety related to potential dangers in an unknown surrounding, promotes manifestations of the research reflex, and makes adaptation of the rats to novel conditions more rapid.PubDate: 2015-01-15

Abstract: Neurons with the presence of c-Fos protein, the product of expression of the “early’ c-fos gene, were detected in the cervical region of the spinal cord of rats performing stereotypic operant food-procuring movements by the forelimb. An immunohistochemical technique was used; the presence of c-Fos was interpreted as a correlate of the activated state of the respective neurons. Effects of suppression of the activity of neuronal NO synthase (nNOS) provided by systemic injections of a selective blocker of this enzyme, 7-nitroindazole (7-NI), were studied under the above conditions. In the absence of 7-NI, the main foci of Fos-immunoreactivity in the spinal segments C6 and C7 were observed in laminae 2i, 3, and 4 of the gray substance, while after injection of this blocker these were found in laminae 3, 4, and 6 and also in the motor nuclei (lamina 9). In animals that performed repetitive food-procuring movements and were preliminarily injected with 7-NI, significantly greater mean numbers of Fos-immunoreactive neurons were found in slices of the gray matter, as compared with the respective figures in rats with no suppression of nNOS activity (54.4 ± 0.7 cells in a 40 μm-thick slice ipsilaterally with respect to the working limb, as compared with 31.7 ± 1.1 cells, P < 0.05). Thus, expression of the c-fos gene in certain regions of the cervical part of the spinal cord increases significantly under conditions of 7-NI-induced suppression of NO production; this is observed in rats realizing repeated movements for a long time.PubDate: 2015-01-15

Abstract: We examined changes in the characteristics of innervation of the upper limb and peculiarities of control of the cardiovascular system in 53 male workers (riveters and fitters in an aircraft plant) who were for a long time subjected to the influence of local vibration and noise in the course of their professional activity. As was found, the mean intragroup threshold of vibration sensitivity of a finger of the working hand in these subjects significantly (P < 0.001) exceeded both normative values and corresponding values in the control group. The respective negative shifts were intensified with increase in the professional experience duration. The mean velocity of transmission of an excitation volley along motor fibers of the n. medianus and n. ulnaris of the working limb in the main group was lower by about 9% (P < 0.05) as compared with the respective index in the control group. Transmission via sensory fibers innervating the corresponding regions of the palm was slowed down by more than 20% (P < 0.05). The residual latency at generation of M responses of the palm muscles in the main group was, on average, 6% longer than in the control (P < 0.05). The mean latency of the evoked cutaneous sympathetic potential at stimulation of the finger of the contralateral palm and recording from the palm and dorsum of the hand also significantly (P< 0.05) exceeded the analogous control value. Results of five standard clinical cardiovascular tests (change in the systolic arterial pressure in the orthostatic test, change in the diastolic pressure at realization of an isometric effort by the palm muscles, calculation of the 30/15 ratio of cardiointervals in the orthostatic test and of the coefficients of duration of these intervals in the Valsalva and deep breathing tests) showed that pathological and boundary values of these indices were found in the main group in 60.3, 32.0, 26.0, 36.0, and 34.0% of the examined persons, while analogous cases in the control group were exceptional. Thus, the long-lasting influence of the intense professional activity-related vibration/noise factor results in the formation of demyelinating polyneuropathy in the upper limb nerves with the involvement of motor fiber terminals and sympathetic postganglionic fibers in the pathological process. Changes in the indices of the cardiovascular tests in subjects of the main group demonstrate that these persons frequently suffer from disorders of the peripheral and, probably, central mechanisms of autonomic control of the cardiovascular system. This results in the development of a syndrome of progressive autonomic insufficiency (with prevalence of insufficiency of the sympathetic mechanisms).PubDate: 2014-12-01

Abstract: This review deals with the processes of coordination of central motor commands (CMCs) that arrive at human arm muscles in the course of realization of “two-joint” voluntary isometric efforts. The dependence of formation of such motor events on changes in the direction of the generated effort is described. Differences between patterns of co-activation of the studied arm muscles under conditions of isometric contractions are presented. Based on the obtained data, directions of the developed efforts are classified as coinciding and, correspondingly, easier for realization (flexion–flexion and extension–extension in both joints), and as discordant “inconvenient” (extension in the shoulder joint–flexion in the elbow joint and flexion in the shoulder joint–extension in the elbow joint). Programming of coactivation of flexors and extensors of the shoulder and elbow joints seems to be possible at the level of CMCs. Predominant sectors of the activity of separate functional muscle groups during realization of the studied efforts are estimated. We found that the orientation of such sectors depends, in most cases, on the orientation of the effort vector but not on the position of the limb within the horizontal plane.PubDate: 2014-12-01

Abstract: We studied possible neuroprotective effects of an experimental preparation, mitochondrin-2 (М-2), on manifestations of a neurodegenerative phenotype in adult Drosophila melanogaster mutants by the swiss cheese (sws) gene and flies with functional knockout of this gene in glia using the Gal4-UAS system. We analyzed the state of brain tissues in histological slices and estimated the level of penetrance and the dimension of degeneration zones. After the fly larvae were fed with М-2, the penetrance of the neurodegenerative phenotype in adult sws gene mutants decreased significantly (by 25%), and dimensions of the neurodegeneration zones in the brain of fruit flies with silencing of the sws gene in gliocytes also decreased (by 31.5%, on average). In the case where we used М-2 during the imago stage, changes in the characteristics of neurodegeneration were not observed.PubDate: 2014-12-01

Abstract: We detected changes in the gene c-fos expression induced by activation of muscle afferents in the rat spinal cord after systemic introduction of reserpine (irreversible suppressor of vesicular transporter of monoamines, 1.5 mg/kg, intraperitoneally) and with no action of this agent. Numbers of Fosimmunoreactive (Fos-ir) neurons were calculated in the gray matter of the lumbar spinal segments after unilateral vibrational stimulation (VS) of the Achilles tendon of the mm. gastrocnemius–soleus. In the spinal cord of rats preliminarily injected with reserpine, greater numbers of Fos-ir neurons were observed; these units were localized mostly in layers 4–7 and in the nucl. intermediolateralis (35.4 ± 1.6 and 16.7 ± 0.9 positive neurons per 40 μm-thick slice) of segments L1–L2, and also in layers 4–7 and layer 9 (Fos-ir motoneurons) of segments L4–L5 (51.7 ± 3.4 and 11.4 ± 1.5 labeled units, respectively). The numbers of activated cells in the above structures of the spinal cord after VS but without preliminary injections of reserpine were, on average, 25.6 ± 1.4 and 3.5 ± 0.5, 27.8 ± ± 0.9 and 6.9 ± 0.3 units, respectively. Most ipsilateral Fos-ir motoneurons (86%) were localized in the lateral pool of layer 9, and only 14% of labeled motoneurons were localized in its medial regions. The results obtained show that weakening of monoaminergic influences resulting from administration of reserpine is accompanied by increase in the activity of intraspinal neuronal networks activated by proprioceptive afferent volleys, and the effects of the above inputs on spinal motoneurons and sympathetic preganglionic neurons are intensified. Weakening of inhibitory control, realized by inhibitory interneurons in the pathways of transmission of excitatory influences from muscle afferents to motoneurons, which was observed in our experiments after suppression of monoaminergic modulatory systems, can be considered a significant factor responsible for the development of rigidity/spasticity of the limb muscles manifested in neurodegenerative diseases and after traumas of the spinal cord.PubDate: 2014-12-01

Abstract: In chronic experiments on 20 mongrel male rats of pubertate age (3 months), we studied the electrical activity of the structures of the limbico-neocortical system and reactions of self-stimulation of the positive emotiogenic zones in the ventralateral hypothalamus under conditions of addiction to vapors of an organic solvent, No. 646. It is shown that the state of addiction to inhalant vapors results in modifications of behavioral reactions, modulation of electrical activity in the neocortex, hippocampus, and medial olfactory region with increases in the powers of some spectral components, and intensification of the reaction of self-stimulation of the positive emotiogenic zones in the ventralateral hypothalamus.PubDate: 2014-12-01

Abstract: The recently introduced “squatting test” (ST) utilizes a simple postural change to perturb the blood pressure and to assess baroreflex sensitivity (BRS). In our study, we estimated the reproducibility of and the optimal testing interval between the STs in healthy volunteers. Thirty-four subjects free of cardiovascular disorders and taking no medication were instructed to perform the repeated ST at 30-sec, 1-min, and 3-min intervals in duplicate in a random sequence, while the systolic blood pressure (SBP) and pulse intervals were measured. Baroreflex sensitivity was estimated by plotting reflex increases and decreases in the SBP and succeeding pulse intervals during stand-to-squat and squat-tostand maneuvers, respectively. Correlations between duplicate BRS data at each testing interval were analyzed by the Pearson’s correlation coefficient, while agreements were assessed by Bland-Altman plots. Two measurements of BRS during stand-to-squat and squat-to-stand maneuvers demonstrated significant correlations at both 1-min and 3-min intervals, while at 30-sec intervals correlation was poor. Correlation coefficients became considerably greater in each maneuver as the measurement interval was increased from 30 sec to 3 min. Our results suggest that the testing interval in the ST should be at least 1 min long, but ideally it should be longer than or equal to 3 min, to assess the baroreflex adequately.PubDate: 2014-12-01

Abstract: We studied the peculiarities of emotional reactions and behavior of old rats in the open field test under conditions of self-stimulation of the ventrolateral and ambivalent zones of the ventromedial hypothalamus either provided in isolation or combined with injections of melatonin. Isolated selfstimulation and self-stimulation combined with introduction of melatonin (six sessions) exerted mostly activating influences on the system of positive emotional reactions. Chronic self-stimulation exerted activating effects on the cerebral mechanisms responsible for negative emotional behavior and increased the levels of motor excitation and emotionality (autonomic behavior manifestations) in animals in the open field test, i.e., induced manifestations of emotional stress in experimental rats. Hypothalamic selfstimulation and injections of melatonin exerted modulating inhibitory effects on the system of negative reinforcement, i.e., decreased psychomotor excitation. The indices of orientation/searching (vertical) activity and the number of episodes of grooming increased, while the latency of coming out from the field center decreased. The data obtained indicate that melatonin possesses anxiolytic and antistress properties mediated by its influence on the reinforcing cerebral systems.PubDate: 2014-12-01

Abstract: We analyzed changes in the spectral powers of different EEG frequency ranges and levels of coherence of the respective oscillations under conditions of passive perception of the smell of isoamyl acetate (pear essence) by humans in the resting state. Depending on a subjective estimate of the smell of isoamyl acetate, its presence per se caused increases in the mean levels of coherence of high-frequency a-subrange oscillations in all tested persons, which can be indicative of intensification of internal mental activity and increase in readiness to react. In the tested persons estimating the used olfactory stimulus as negative, the coherence of α2- and β1-oscillations in the central cortical areas and in the frontal and occipital zones decreased. In the tested persons with the positive subjective estimate of the isoamyl acetate smell, the coherence increased also in the a1-subrange during the action of this olfactory stimulus. Therefore, we obtained indications that activation of the olfactory analyzer is capable of changing the functioning of neuronal networks of the human brain in the resting state, and the pattern of these alterations partly depends on a subjective hedonic estimate of one smell or another.PubDate: 2014-12-01

Abstract: Coherent relations between EEG signals of five frequency ranges recorded from different cortical sites were evaluated in 8- to 12-year-old children with congenital and acquired visual dysfunctions; the results were compared with those observed in children with normal vision. In visual dysfunctions, the coherence was, in general, higher for slow-wave ranges and weaker for the alpha EEG range. These facts are indicative of probable intensification of brainstem influences of the cortex. Specific features of the coherence dependent on the time of development of visual dysfunctions were identified.PubDate: 2014-12-01

Abstract: In rats, we examined the organization of cortical zones within which microstimulation (MES) evoked contractions of separate groups of the forelimb muscles. Examination was performed under conditions of pictrotoxin-induced kindling and within the postkindling period. In kindling rats, the areas of cortical zones responsible for forelimb movements was significantly (more than two times) greater than those in intact animals (P < 0.05). Microstimulation-evoked effects in postkindling were rather similar to those observed under kindling conditions. When longer (1-sec-long) stimuli were used for MES within both kindling and postkindling periods, the duration of motor responses was significantly (P < 0.05) greater than in the control. The enhancement of the areas of cortical representation of the forelimb muscles under conditions of kindling-induced epileptiform activity probably reflects systemic modifications in the motor cortex neuronal systems.PubDate: 2014-12-01

Abstract: We examined the involvement of nicotine acetylcholine receptors (nAChRs) in the generation of background synaptic activity in rat retinal ganglion cells (RGCs). Experiments were carried out in vitro on RGCs of the isolated retina of 21-day-old rats using the patch-clamp technique in the whole cell configuration (voltage-clamp mode). The neurons did not undergo enzymatic processing in order to provide more adequate preservation of the properties of cells of the native retina. In 15 examined cells, the resting membrane potential (RMP) was –62 ± 2 mV, on average, the input resistance of the membrane was 573 ± 68 MΩ, and the membrane capacitance was 34 ± 5 pF. The effects of blocking of nAChRs were estimated using bеnzohexonium (BH) in a 450 μM concentration. Background excitatory postsynaptic currents (EPSCs) in RGCs appeared, under the conditions of our experiments, with the mean frequency of 3.1 ± 0.8 sec–1 (n = 10). Application of BH resulted in suppression of the currents in six cells. Significant selectivity of the effects of these blockers was observed; it affected mostly high-amplitude EPSCs (40–100 pA). The effect of BH was mostly reversible. Our results show that activation of nAChRs modulate electrical activity in RGCs; probably, these receptors mediate certain types of synaptic transmission. The general RGC population is rather heterogeneous from the aspect of the presence/absence of nAChRs and distribution of separate subtypes of the latter.PubDate: 2014-12-01